Silencer for gas discharging devices employing means for reducing drag

ABSTRACT

A silencer for muffling of noises in a gas pressure exhaust system such as the exhaust systems for air operated power cylinders, tools and the like as well as internal combustion engines of the two- and four-cycle type by the utilization of guiding surfaces for directing the gases under pressure into chambers where the gases acquire a rotary or whirling movement about a stationary axis within the silencer and are expelled after such rotary action has dissipated their energy, aided by means for reducing the back pressure or drag of the guiding surfaces on the gases.

[ Oct. 23, 1973 tates atem 1 Perrine 951,770 3/1910 Miller...... 181/703,399,597 9/1968 181/58 89/14 D SILENCER FOR GAS DISCHARGING DEVICESEMPLOYING MEANS FOR REDUCING DRAG Perrine .m X m 09 0 99 111 ll 53 n O S.m m B d r a h .w R H e m m m E w a .m r P 6 6 X 0 B P9 :0 e5 6 r eZ P nrm Ma WN n m n e v n I Q 7 Assistant Examiner-Pat Salce [22] Filed 1973Att0mey-Warren F. B. Lindsley [21] Appl. No.: 327,695

ABSTRACT Isl/49, Isl/7O A silencer for muffling of noises in a gaspressure ex- F01 haust system such as the exhaust systems for air oper-181/41 49, 58 66 ated power cylinders, tools and the like as well as in-[52] U.S. [51] Int. Cl.

Field of Search ternal combustion engines of the twoand four-cycle 4 D 3M s/ 69 200 3.) s8 50 23 B m 3 c m 3 4 B 3 3 .B 7 4 7 1 0O 1 type by theutilization of guiding surfaces for directing the gases under pressureinto chambers where the gases acquire a rotary or whirling movementabout a stationary axis within the silencer and are ex References CitedUNITED STATES PATENTS 6/1950 McLeod.............. 2/1912 pelled aftersuch rotary action has dissipated their energy, aided by means forreducing the back pressure or drag Boeck Isl/70 of the guiding surfaceson the gases. Miller 181/70 16 Claims, 12 Drawing Figures 2,511,3591,017,003 Kenney 1,002,801 9/1911 981,584 l/l9l1 law/T.

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SHEET 3 0F 3 SILENCER FOR GAS DISCHARGING DEVICES EMPLOYING MEANS FORREDUCING DRAG BACKGROUND OF THE INVENTION This invention relates todevices for muffling and silencing of noises in exhaust systems such asthe exhausts from compressed air operated power cylinders, tools or thelike as well as internal combustion engines of the twoand four-cycletype.

FIELD OF THE INVENTION This invention is particularly directed to noveland improved muffling devices for silencing exhaust noises by directingexhaust gases under pressure into a chamber where they acquire a rotaryor whirling movement about a plurality of stationary axes within thechamber and escape therefrom after their energy is dissipated in suchrotary or whirling movements.

DESCRIPTION OF THE PRIOR ART Heretofore mufflers have been used for thedissipation of exhaust noises wherein the exhaust stream of gases isdiverted byfins or ribs of a spider means within the muffler. Othermufflers have reduced the exhaust noises of an exhaust system in asilencing chamber by the utilization of porous walls through which theexhaust fluid is diffused. These porous walls have been formed'ofcellulose fibrevsheet material impregnated with a phenolic resin.

In firearms, attempts were made to dissipate the energy of the powdergases by giving them a rotary or whirling movement in a suitable chamberwith the gases gradually escaping from the chamber to atmosphere.

In all cases, the muffling was only partially effective and the mufflerdevices were not effective when used with a constant source of exhaustgases, since their exhaust to atmosphere after dissipation of theirenergy was too slow and applied a back pressure to the power generatingdevice such as the power cylinder and internal combustion engine whichreduced its efficiency. Therefore, a need exists for a new and improvedmuffler or silencer which may operate on a continuous stream of exhaustgases to effectively muffle or silence its exhaust gases withoutdestroying the efficiency of the associated power generating device.

SUMMARY OF THE INVENTION In accordance with the invention claimed, a newand improved muffler or silencer is provided for an intermittent orcontinuous source of exhaust gases under pressure which dissipates theenergy of the exhaust gases by rotary and whirling movements about aplurality of stationary 'axes progressively positioned in a chamberbefore the gases are expelled to atmosphere.

It is, therefore, one object of this invention to provide a new andimproved muffler or silencer.

Another object of this invention is to provide an improved muffler forsilencing the nosies of exhaust gases by giving them new rotary orwhirling movements in a suitable chamber.

A further object of this invetnion is to provide an improved muffler forsilencing the noises of exhaust fluids by giving them a series of rotaryor whirling movements about a series of stationary axes as they passthrough a suitable chamber under pressure and/or vacuum supplemental tothe pressure of the exhaust gases.

A still further object of this invention is to provide an improvedmuffler for silencing the noises of exhaust gases by dissipating theirenergy by giving them a rotary or whirling movement in a suitablechamber about axes coincident with the axis of the dissipated gasesbeing exhausted to atmosphere.

A still further object of this invention is to provide a muffler orsilencer for exhaust gases under pressure utilizing gas deflecting meansfor providing the gases with a rotary or whirling motion which isassembled with a minimum number of interchangeable parts.

Further objects and advantages of the invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize this in vention will be pointed out with particularity inthe claims annexed to and forming a part of this specification.

BRIEF DESCRIPTION OF THE DRAWING The present invention may be morereadily described by reference to the accompanying drawings,'in which:

FIG. 1 is a perspective view partially broken away showing a mufflerembodying the present invention;

FIG. 2 is a cross-sectional view of FIG. 1 taken along the line 2-2;

FIG. 3 is a cross-sectional view of FIG. 1 taken along the line 3-3;

FIG. 4 is an enlarged partial view of the exhaust end of the mufflershown in FIG. 1;

FIG. 5 is an enlarged partial perspective view of one of the gas guidingmeans or baffles shownin FIG. 1;

FIG. 6 is a front or end view of the complete guiding means shown inFIG. 5;

FIG. 7 is a cross-sectional view of FIG. 5;

FIG. 8 is an alternate embodiment of the baffle arrangement shown inFIGS. 1-7;

FIG. 9 is a modification of the baffles shown in FIGS. 1-7;

FIG. 10 is an end view of FIG. 9;

FIG. 11 is a cross-sectional view of an assembly of the baffles shown inFIG. 9 mounted on a pin; and

FIG. 12 is a modification of the assembly of the baffles shown in FIG.11 mounted without the aid ofa pin.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring more particularly to thedrawing by characters of reference, FIGS. 1-7 disclose an improvedmuffler 15 for gas discharge devices such as internal combustionengines, air motors or the like. As shown in FIG. 1, for purposes ofillustration only, muffler 15 is mounted on the end of an exhaust pipe16 of a gas discharge device such as a chain saw driven by a gasolinemotor.

Muffler 15 comprises a hollow housing 17 comprising, for example, twocylindrical parts 17' and 17" interconnected by a fan housing 18. A pipe19 is attached to one end of part 17' of the cylindrical housing 17 forinsertion into or over the exhaust pipe 16 of the chain saw or other gasexhausting device that it is intended to silence. The hollow cylindricalhousing 17 defines a chamber 20 axially aligned with exhaust pipe 16 inpart 17' and having a plurality of deflection devices 21 coaxiallyarranged along its inner cylindrical wall.

Part 17" of the cylindrical housing defines an annular chamber 22 whichis defined by a funnel-shaped flange 23 fastened to the inboard end of ahollow cylinder 24 with a passageway 25 extending through flange 23 andcylinder 24, as shown in FIG. 3. The opposite end of chamber 22 isdefined by an apertured flange 26 which is of substantially the samediameter as the inside diameter of part 17" with an aperture 27extending therethrough in alignment with passage 25 and of substantiallythe same diameter.

An annular chamber 28 is arranged within part 17" of the cylindricalhousing and arranged to receive within its inboard end 29 an exhaustpipe 30 of fan housing 18.

Loosely arranged within part 17" of the cylindrical housing 17 ofmuffler between end 29 and flange 26 and between flange 26 and end 31thereof are a plurality of the deflection devices 21. As noted from FIG.1, all of the deflection devices 21 in annular chambers are arranged inone direction with regard to the gas under pressure moving through themuffler, and all of the deflection devices in annular chamber 28including those around the outside periphery of exhaust pipe 30 of fanhousing 18 extend in the opposite direction with regard to the flow ofgas under pressure through the muffler.

As shown in FIG. 1, cylinder 24 forming within it passageway is slottedalong its length to provide vent openings for the gas under pressurepassing through passageway 25. These slots 34 are arcuate inconfiguration and extend less than 180 around the circumference of theouter wall of cylinder24. Two of the slots 34 on opposite sides of thecircumference of cylinder 24 may extend in the same cross-sectionalplane or they may be a continuation of a spiral moving longitudinallyalong the axis of cylinder 24. One requirement of the slots 34 is thatthey open into the entrance to the deflection devices'32 arrangedaxially along and around the outer periphery of cylinder 24, as willhereinafter be explained in more detail.

Each deflective device 32, as shown in FIGS. 1, 3 and 4, may be formedor molded separately and then 'assembled around cylinder 24 to formapart of the annular chamber 22.'Each deflection device 32 is formedwith a hole, or aperture 34 and when a plurality of them are assembledaxially in like directionaround cylinder 24 they provide a plurality ofpassages or pockets 35 in which the gases expanding out of slots 34 maydissipate their energy. v

Loosely arranged around the outside of the assembly of deflectiondevices 32 and within part 17" are a plurality of deflection devices 21arranged in the same direction as the deflection devices 21 in annularchamber 20.

FIGS. 5, 6 and 7 illustrate enlarged views of deflection device 32 andshow that it comprises a funnelshaped surface 36 which tapers outwardlyto a conical opening, passageor pocket 35. The housing forming pocket 35lies in planes lateral to the axis of the deflection device 32 so that aplurality of the devices may be axially aligned, one fitting into thenext as shown in FIGS. 1 and 4. The gases, as they expand out of slots34 in the cylinder 24, pass into pockets 35 of deflection devices 32where they expand or diverge and are directed by the guiding surfacesforming pockets 35 to assume a whirling or rotary movement about asubstantially circular or annular line or axis in each pocket, wherebyunder the centrifugal action developed by such rotary movement of thegases and the expansion thereof during such action, the gases are causedto dissipate their energy in friction against the inner walls of thesedeflection devices forming pockets 35.

It is the intent ofthis disclosure to disclose a method and means forcontrolling the gases which escape from the exhaust conduit of an enginesuch as an internal combustion engine or an air expansion engine, and tocompel these gases to acquire within successive cells or chambers formedin the muffler a continuous,-expanding rotary or whirling movement aboutthe axis of the muffler. As the gases under pressure from the noiseproducing device are provided with a rotary or whirling movement, theyexpand and lose or dissipate their energy.

Usually the blast of a gas under pressure from an internal combustion orgas expansion typeof engine passes out of the noise producing device ina pencil-like form or core of gas under pressure. This core of gas,which until this point of expansion has not been made to dissipate itsenergy in a rotary or whirling movement in a silencing device, thereforeoccasions some noise of explosion. In the device and method claimedherein, this noise of expansion of the explosive gases under pressure iscontrolled-or substantially eliminated.

In the devices disclosed, the gases of expansion are deflected or turnedout of a straight line in a sequence of operations to eliminate orsubstantially reduce the noise of gas expansion. v

Although the method and devices disclosed and claimed herein utilizesome principles heretofore known, the claimed configuration is animprovement over the teachings in the following US. patentsan'd othersthat may appear in the art: US. Pat. 'Nos. 916,885, H. P. Maxim;951,770,]. M. Miller; 958,934,

H. P. Maxim; 958,935, H. P. Maxim; 1,066,898, W. R.

Gray; 3,399,597, W.E. Perrine.

The silencing effect accomplished only to.a limited extent by Maxim inhis patents above identified is not enough to silence the exhaust gasesof modern internal combustion and gas expansion engines. Therefore,further'deflection and expansion of the expanding'gases' of these noiseproducing devices mustbe effected in a new, improved and controlledmanner.

As disclosed herein, the expanding gases are first expanded anddeflected in a controlled manner in part 17 of the cylindrical housing17 forming muffler 15, before they are transmitted through fan housing18 to annular chambers 28 and 22, where they are deflected and expandedfurther by deflection devices 21 and 32 therein.

As the core or pencil of gas under pressure leaves the noise producingdevice such as, for example, the exhaust pipe 16 of a gas dischargingdevice, a part of these gases expands in the annular chamber 20 andstrikes the open edges of deflection devices 21 as these gases movethrough the muffler. v

Deflection devices 21, as shown in FIGS. 1, 2 and 4, comprise an annulardisc having a turned-over, scrolltype outer edge 40 forming a pocket 41within it for whirling the gases directed into it. A plurality of thesedeflection devices are mounted in alignment axially along part 17' ofthe cylindrical housing forming muffler 15with their scroll openingfacing the oncoming stream of gas under pressure to receive the gases.It should be recognized that the opening 42 formed in each deflectiondevice 21, as shown, is slightly larger than the inside diameter of theexhaust pipe 16 so that the opening and deflected gases beingcontrolledmay readily pass rearwardly along the muffler toward end 33 ofpart 17' of the cylindrical housing and readily pass into the openingleading into fan housing 18. The pockets in the deflection plates causethe gases enter ing each pocket to assume a whirling or rotary movementabout a substantially circular or annular line or axis, whereby underthe centrifugal action developed by such rotary movement the gases ofexpansion are caused to dissipate their energy in friction against theinner walls of these deflection devices forming the pockets 41.

As shown in part 17" of the cylindrical housing, the deflection devices21 arranged around the exhaust pipe 30 of fan housing 18 in annularchamber 28 are the same deflection devices 21 arranged in chamber 20.The only difference is this assembly of deflection devices 21 is thatthe scrolls open in the opposite direction to those in annular chamber20.

Gases expanding out of exhaust pipe 30 are deflected off of the surface43 of flange 26 into the openings of the scrolls of deflection devices21, wherein they dissipate their energy as heretofore explained. Sincethese deflection devices fit loosely around exhaust pipe 30 and theinside periphery of part 17" of the cylindrical housing between flange26 and end 29 of part 17' of muffler 15, many pockets are available forthe dissipation of the energy of the expandinggases.

As shown in annular chamber 22, the same deflection devices 21 arearranged axially along the longitudinal axis of part 17" of thecylindrical housing between flange 26 and the funnel-shaped flange 23.The only difference here from that shown in chamber 28 is thatdeflection devices 21 are so arranged that their scrolls open in theopposite direction to those shown in annular chamber 28.

Gases expanding out of aperture 27 in flange 26 are deflected off thesurfaces of funnel-shaped flange 23 and into the openings of the scrollsof deflection devices 21, wherein they dissipate their energy asheretofore explained. Deflection devices 21, which fit loosely aroundcylinder 24 within part 17'' of the cylindrical housing, are arrangedwith their scrolls opening opposite to those just described in annularchamber 22 so that gases escaping outwardly of part 17" of thecylindrical housing may be further expanded and caused to dissipatetheir energy.

As noted from FIGS. 1, 3 and 4 of the drawings, the gases under pressurepassing through an aperture in funnel-shaped flange 23 pass throughpassage 25 in cylinder 24 to atmosphere with some of the gas beingdiverted through slots 34 in cylinder 24 and into pockets 35 ofdeflection devices 32, where the energy of the gases is still furtherdissipated before being exhausted to atmosphere.

In order to reduce or overcome the drag or resistance to the exhaustgases discharged from a motor or the like in order to avoid reducing itsoperating efficiency, a fan, blower or any other form of suction meansand- /or pressure-generating means may be used for aiding the movementof the gases through the muffler to atmosphere.

As shown in FIG. 1, the fan housing 18 with its fan mechanism isarranged between parts 17' and 17" of the muffler housing for aiding indriving the exhaust gases through the muffler.

It should be recognized that this fan mechanism also may be placedbetween the exhaust pipe 16 of the gas discharging device and themuffler or at the discharging end 31 of part 17" of the muffler, if sodesired.

Thus, as the gases of expansion or explosion of a noise producing deviceare directed into muffler 15, the core of gases first partially expandsand is directed in a whirling motion in annular chamber 20 to lose partof its energy of the resulting expansion-generated noise. Next, the coreof gas and its trailing portion partly expanded in annular chamber 20moves into annular chamber 28, where it further expands, and is directedin a whirling motion to reduce further its energy. Thirdly, the gas andits trailing expanded portion moves into annular chamber 22, where it isagain expanded and directed to lose or dissipate more of its energy,after which it moves out of end 31 of the muffler through passageway 25,substantially reduced in pressure and substantially noiseless.

FIG. 8 is an alternate arrangement of the slot 34 and associatedopenings in the deflection devices 32 as assembled in FIGS. 1 and 4. InFIG. 8 the slots 34 are formed in the slotted cylindrical wall 24 suchthat edge 2 of slots 33 is inclined at an angle of 10 with a lineextending perpendicularly to the longitudinal axis of the cylindricalwall 24. As shown also in FIG. 8, the slope of funnel-shapedconfigurations of deflection devices 32 loosely mounted around thecylindrical wall 24 are substantially 60 to a line extendingperpendicularly to the longitudinal axis of the cylindrical wall 24.This particular arrangement of cooperating passages aids in direction ofthe expanding gases into pockets 35 of the deflection devices fordissipating of the energy of these gases and the resulting noises of gasexpansion.

FIGS. 9 and 10 illustrate a modification of the deflection devices 32wherein the funnel-shaped flange 47 forming the deflection device 48 isprovided with shoulders 49 on opposite sides, each of which are providedwith apertures 50 extending therethrough longitudinally of aperture 51formed along the devices longitudinal axis. As noted from FIG. 9, thedeflection device opens into an arcuate-shaped, flared end 52. The otherside 53 of the flared end 52 is also of an arcuate configuration,curving outwardly in a direction substantially opposite to the flaredsurface of end 52. When two similarly shaped deflection devices 48 areaxially aligned and held together by rods 54, only one of which isshownin FIG. 11, they form an assembly as shown in FIG. 11. This assembly canthen be assembled around cylindir'cal wall 24 to serve as a gasdisseminator in the manner of deflection devices 32 shown in FIG. 1.

FIG. 12 shows deflection devices 55 of the same general type shown inFIG. 11 without the shoulder and rod or pin arrangement for holding themtogether. Each of the deflection devices is axially aligned along andaround the cylindrical wall 24, as shown.

Although but a few embodiments of the present invention have beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

I claim:

1. A muffler for receiving gas under pressure from a source comprising:

a housing adapted to communicate with said source,

said housing having a gas discharge opening extending therethrough forthe passage of gas under presa plurality of deflecting means mountedalong the inside periphery of said first and second chambers,

said deflecting means each comprising a pocket for receiving thedeflected gases in the chamber along I which they extend for causing thegases to acquire a rotary and whirling movement about an annular axis,

the pockets in said deflection means along said first chamber opening inthe upstream direction of movement of gas under pressure through saidopening-and the pockets in said deflection means downstream of saidflange in said second chamber opening in the downstream direction ofmovement of gas under pressure through said opening, and the pockets insaid deflection means upstream of said deflection means along saidsecond chamber opening in the upstream direction 'of movement of saidgases, and

exhaust means for aiding the movement of said gases under pressurethrough said housing to compensate for the loss of pressure of saidgases in said muffler due to friction of the gases on the surfaces ofsaid pockets. v

2. The muffler set forth in claim 1 wherein:

said exhaust means comprises a fan for aiding in the movement of thegases under pressure through said housing. I 1

3. The muffler set forth in claim 1 wherein:

said exhaust means comprises a suction-type fan.

mounted in said housingbetween said first and second chambers fordrawing the gases under pressure through said first chamber and blowingthe gases through said second chamber.

4. The muffler set forth in claim 1 wherein:

said exhaust means is mounted at one end of said housing, aiding inmoving the gases under pressure through said housing.

5. The muffler set forth in claim 1 wherein:

said first and second chambers divide said housing into two separateparts wherein the only gas communication through said first and secondchambers is through said gas discharge opening.

6. The muffler set forth in claim 5 wherein:

said housing defines an annular opening at one end for receiving adischarge of a gas generating device,

said annular opening opening into one end of said first chamber. Y

7. The muffler set forth in claim 6 wherein:

said deflection means in said first and second chambers extendlongitudinally of said chambers around said annular opening.

8. The muffler set forth in claim 1 wherein:

said deflection means each comprise a circular,

doughnut-shaped configuration having a turnedover edge forming ascroll-like, arcuate configuration along its outer periphery for formingsaid pocket.

9. A muffler for a device discharging gas under pressure comprising:

a housing adapted to communicate with the bore of the gas dischargingdevice,

said housing having an opening extending axially therethrough for thepassage of gas under pressure from the gas discharging device;

three annular chambers axially aligned in said housing each definingsequentially a part of said openthe first andsecond of said chamberseach comprising a plurality of baffles arranged to extend longitudinallyof said housing and arranged to define with their adjacent edges a partof the periphery of said opening,

a flange at the downstream end of said second chamber extendinglaterally of said housing for deflecting downstream in said housing, i

a plurality of first deflection means mounted along the insideperipheral surfaces of said firstand second chambers for receiving theoutwardly. deflected gases of the gas discharge stream,

- said first deflection means each comprising a pocket for receiving thedeflected gases and causing them to acquire a rotary and whirlingmovement about an annular axis, I i

the pockets in said first deflection means surrounding said firstchamber opening in the 'upsteam direction of movement of gas underpressure through said opening and the pockets in said deflection meansurrounding said second chamber opening in the downstream direction ofmovement of gas under pressure through said opening,

the third of said chambers arranged for receiving the discharge gasunder pressure from said second chamber and comprising a cylindricalhousing surrounding and defining the periphery of a portion of saidopening in said muffler,

said cylindrical member provided with a plurality of slots spacedlyarranged along the longitudinal axis of said cylindrical housing,

a plurality of second deflection means axially arranged along saidcylindrical member and each defining a pocket in communicationwith atleast one of said slots,

each of said pockets of said second deflection means causing said gasdeflected through said slots and into them acquiring a rotary andwhirling move ment about an annular axis to dissipate theirensaid gasesin said muffler after dissipation of a substantial amount of theirenergy in said first and second deflection means being expelled throughsaid opening to atmosphere, and

exhaust means for aiding the movement of said gases under pressurethrough said housing to compensate for the loss of pressure of saidgases in said muffler due to friction of the gases on the surfaces ofsaid pockets.

10. The muffler set forthin claim 9 wherein:

said second deflection means comprises funnelshaped devices with oneresting within the other when assembled.

11. The muffler set forth in claim 10 wherein:

each of said second deflection means defines an opening axially thereofof a slightly larger diameter than said cylindrical member for slidablyfitting thereover.

12. The muffler set forth in claim 11 wherein:

said housing defines an annular opening at one end for receiving adischarge nozzle of a gas generating device,

said annular opening opening into one end of said first chamber.

13. The muffler set forth in claim 12 wherein:

said first deflection means in said first chamber extend longitudinallyof said housing around said annular opening and said first deflectingmeans in said second chamber extend longitudinally of said housingaround said second deflection means.

14. The muffler set forth in claim 13 wherein:

said exhaust means comprises a fan for aiding in the movement of thegases under pressure through said housing.

15. The muffler set forth in claim 13 wherein:

said exhaust means comprises a suction-type fan mounted in said housingbetween said first and second chambers for drawing the gases underpressure through said first chamber and blowing the gases through saidsecond chamber.

16. The muffler set forth in claim 13 wherein:

said exhaust means is mounted at one end of said housing aiding inmoving the gases under pressure through said housing.

1. A muffler for receiving gas under pressure from a source comprising:a housing adapted to communicate with said source, said housing having agas discharge opening extending therethrough for the passage of gasunder pressure, a pair of cylindrical chambers in said housing, eachdefining therethrough sequentially a part of said opening, a flangehaving an aperture therethrough forming a part of said opening withinsaid second chamber and extending laterally of said housing, said flangedeflecting upstream gas under pressure expanding outwardly of saidopening in said second chamber, and a plurality of deflecting meansmounted along the inside periphery of said first and second chambers,said deflecting means each comprising a pocket for receiving thedeflected gases in the chamber along which they extend for causing thegases to acquire a rotary and whirling movement about an annular axis,the pockets in said deflection means along said first chamber opening inthe upstream direction of movement of gas under pressure through saidopening and the pockets in said deflection means downstream of saidflange in said second chamber opening in the downstream direction ofmovement of gas under pressure through said opening, and the pockets insaid deflection means upstream of said deflection means along saidsecond chamber opening in the upstream direction of movement of saidgases, and exhaust means for aiding the movement of said gases underpressure through said housing to compensate for the loss of pressure ofsaid gases in said muffler due to friction of the gases on the surfacesof said pockets.
 2. The muffler set forth in claim 1 wherein: saidexhaust means comprises a fan for aiding in the movement of the gasesunder pressure through said housing.
 3. The muffler set forth in claim 1wherein: said exhaust means comprises a suction-type fan mounted in saidhousing between said first and second chambers for drawing the gasesunder pressure through said first chamber and blowing the gases throughsaid second chamber.
 4. The muffler set forth in claim 1 wherein: saidexhaust means is mounted at one end of said housing, aiding in movingthe gases under pressure through said housing.
 5. The muffler set forthin claim 1 wherein: said first and second chambers divide said housinginto two separate parts wherein the only gas communication through saidfirst and second chambers is through said gas discharge opening.
 6. Themuffler set forth in claim 5 wherein: said housing defines an annularopening at one end for receiving a discharge of a gas generating device,said annular opening opening into one end of said first chamber.
 7. Themuffler set forth in claim 6 wherein: said deflection means in saidfirst and second chambers extend longitudinally of said chambers aroundsaid annular opening.
 8. The muffler set forth in claim 1 wherein: saiddefleCtion means each comprise a circular, doughnut-shaped configurationhaving a turned-over edge forming a scroll-like, arcuate configurationalong its outer periphery for forming said pocket.
 9. A muffler for adevice discharging gas under pressure comprising: a housing adapted tocommunicate with the bore of the gas discharging device, said housinghaving an opening extending axially therethrough for the passage of gasunder pressure from the gas discharging device; three annular chambersaxially aligned in said housing each defining sequentially a part ofsaid opening, the first and second of said chambers each comprising aplurality of baffles arranged to extend longitudinally of said housingand arranged to define with their adjacent edges a part of the peripheryof said opening, a flange at the downstream end of said second chamberextending laterally of said housing for deflecting downstream in saidhousing, a plurality of first deflection means mounted along the insideperipheral surfaces of said first and second chambers for receiving theoutwardly deflected gases of the gas discharge stream, said firstdeflection means each comprising a pocket for receiving the deflectedgases and causing them to acquire a rotary and whirling movement aboutan annular axis, the pockets in said first deflection means surroundingsaid first chamber opening in the upstream direction of movement of gasunder pressure through said opening and the pockets in said deflectionmeans surrounding said second chamber opening in the downstreamdirection of movement of gas under pressure through said opening, thethird of said chambers arranged for receiving the discharge gas underpressure from said second chamber and comprising a cylindrical housingsurrounding and defining the periphery of a portion of said opening insaid muffler, said cylindrical member provided with a plurality of slotsspacedly arranged along the longitudinal axis of said cylindricalhousing, a plurality of second deflection means axially arranged alongsaid cylindrical member and each defining a pocket in communication withat least one of said slots, each of said pockets of said seconddeflection means causing said gas deflected through said slots and intothem acquiring a rotary and whirling movement about an annular axis todissipate their energy, said gases in said muffler after dissipation ofa substantial amount of their energy in said first and second deflectionmeans being expelled through said opening to atmosphere, and exhaustmeans for aiding the movement of said gases under pressure through saidhousing to compensate for the loss of pressure of said gases in saidmuffler due to friction of the gases on the surfaces of said pockets.10. The muffler set forth in claim 9 wherein: said second deflectionmeans comprises funnel-shaped devices with one resting within the otherwhen assembled.
 11. The muffler set forth in claim 10 wherein: each ofsaid second deflection means defines an opening axially thereof of aslightly larger diameter than said cylindrical member for slidablyfitting thereover.
 12. The muffler set forth in claim 11 wherein: saidhousing defines an annular opening at one end for receiving a dischargenozzle of a gas generating device, said annular opening opening into oneend of said first chamber.
 13. The muffler set forth in claim 12wherein: said first deflection means in said first chamber extendlongitudinally of said housing around said annular opening and saidfirst deflecting means in said second chamber extend longitudinally ofsaid housing around said second deflection means.
 14. The muffler setforth in claim 13 wherein: said exhaust means comprises a fan for aidingin the movement of the gases under pressure through said housing. 15.The muffler set forth in claim 13 wherein: said exhaust means comprisesa suction-type fan mounted in said housing between said first and sEcondchambers for drawing the gases under pressure through said first chamberand blowing the gases through said second chamber.
 16. The muffler setforth in claim 13 wherein: said exhaust means is mounted at one end ofsaid housing aiding in moving the gases under pressure through saidhousing.